1. Field of the Invention
The present invention relates to a sensing and warning system for ladder load, and particularly to a sensing and warning system composing of sensing means, a recording and calculation device, and an alarm for detecting, recording and evaluating the ladder load, and sending an alarm signal in case the ladder load exceeds its maximum withstandable value.
2. Description of the Prior Art
A ladder, a foldable or an extension type, is widely used in domestic and professional construction work.
FIG. 1 is a drawing of a common foldable ladder. The ladder has at least two pairs of ladder legs 11, 12, each pair of legs 11 and 12 is provided with a pair of feet 111, 112 and 121, 122 respectively, and each of them wears a mat 15 for increasing friction with the ground so as to prevent accidental slipping. A platform 13 is hinged to the top ends of the legs 11, 12 and a pair of hasps 14 is provided each releasably secured to the opposite leg 11 or 12 such that the ladder is developed in a derrick figure when in use.
For ensuring the use""s safety, both the manufacturer and the inspection authority are very careful in upgrading the construction material and design criteria and always reminding the user how to use a ladder securely without overloading. As a matter of fact, people occasionally hear of accidents arising from misuse of ladders such as overloading and ignoring safety rules. Relief measures for victims"" rehabilitation often cause great trouble to the manufacturer, the employer and the insurance company.
In order to overcome the problems inherent to the conventional ladders described above, the present inventor has studied this matter for a long time and developed the present invention.
Accordingly, it is an object of the present invention to provide a sensing and warning system for ladder load to be installed in the ladder feet for detecting, recording and calculating the ladder load, and sending an alarm signal in case the ladder load is dangerous.
It is another object of the present invention to provide a sensing and warning system for ladder load whose recorded and calculated loading data can assist to identify the responsibility in case of the occurrence of accident.
It is one more object of the present invention to provide a sensing and warning system for ladder load that the sensing means can be equipped in the hasp between two ladder legs so as to promptly warn the user entrained on the ladder in a critical situation such as collapse of the ladder by slipping.
To achieve these and other objects described above, the sensing and warning system for ladder load according to the present invention is composed of sensing means, a recording and calculation device, and an alarm. The sensor means further includes a connecting member, a sensor and a base. The connecting member is formed in a block structure and is concealed and engaged to each ladder foot. A sensor is installed under the connecting member, the base is located beneath the sensor but can be enclosed by a foot mat. The sensor is connected to a CPU of the recording and calculation device whose output terminal is further connected to the alarm. With this structure, the sensing means detects the ladder load at any moment and sends the detected data to the recording and calculation device for evaluation. If the ladder load exceeds the predetermined maximum allowable value, the alarm delivers a warning signal to the user.